Ip Addresses And Dhcp - Allied Telesis AR410 User Manual

Getting Started with the Graphical User Interface (GUI)
Problem
Solutions
Problem
Solution
Problem
Solutions
Software Release 2.7.1
C613-02021-00 REV F
A device on your LAN or DMZ can access a service on the Internet even
though it should be blocked.
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The most likely cause of this problem is an incorrect outgoing rule. Check
that:
• Rules intended to block traffic have an action of "Deny".
• The firewall is processing the rules in the order you expected, and that
specific rules (e.g. block IP address x from using FTP) have lower
numbers than general rules (e.g. allow all outgoing FTP requests).
• The rules apply to the correct IP services (by name or port number).
• The IP addresses the rules apply to are entered correctly, and actually
belong to the specified devices.
• The rules apply to the correct days and time.
■
If an IP address-based rule exists to block traffic from this particular
device, check that the device has a permanently-assigned IP address.If the
router is assigning IP addresses as a DHCP server, you can give the
required device a permanent IP address by making it a static entry
(Configuration > DHCP Server).

IP Addresses and DHCP

You have selected Quick Start > WAN > DHCP, but the router hasn't been
given an IP address.
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Check that the router's domain and host name are correct (Configuration >
System > General).
■
Check that the DHCP server can reach the router, by pinging the router
from the DHCP server. Note that you will not get a response if Respond to
ping is unchecked on the Firewall Policy Options page (Configuration >
Firewall > Interfaces > Policy options tab). This option is checked by
default.
The router is enabled as a DHCP server, but cannot assign an IP address to a
host.
■
Reboot the host machine.
■
Check the host's TCP/IP settings, to make sure that the host is set to obtain
its IP address dynamically:
In Windows 95/98, click Settings > Control Panel > Network. Select TCP/
IP and click Properties. Click Obtain an IP address automatically.
In Windows 2000, click Settings > Control Panel > Network and Dial-up
Connections > Local Area Connection > Properties. Select Internet
connection (TCP/IP) and click Properties. Click Obtain an IP address
automatically.
■
Check that the DHCP server has a large enough range of addresses
(Configuration > DHCP Server).
■
Check that the router's link to the LAN is functioning, by checking the
interface status (Monitoring) and that the link LED is lit (see "Traffic Flow
and Network Address Translation (NAT)" on page 44).
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